Roman Numerals/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim and Moby are walking home from school. Moby looks unhappy. TIM: Hey, are you feeling okay? MOBY: Beep. Moby's arm opens, revealing a control panel. Flames shoot out, and the two are teleported back in time. TIM: Whoa, whoa. Cut it out! No. Oh, no, no. I've got to be home for dinner! The two materialize in a town square in ancient Rome. TIM: Oh, man! Mom's going to kill me! Moby holds out his control-panel arm. Its monitor displays a string of Roman numerals: CXIX. TIM: Hey, what's wrong with your clock? Tim looks around. Rome appears deserted except for a young man selling newspapers. TIM: Oh, man. MOBY: Beep. TIM: Well, we're in ancient Rome, and they didn't write numbers the way we do. We should be okay, though. I remember learning Roman numerals in Mrs. Diotte's class a few years ago. They are standing next to a large sundial. TIM: Our system for writing numbers uses Hindu-Arabic numerals. You know, zero, one, two, three, four, and so on. An image shows the sundial with ordinary numerals replacing the Roman numerals. TIM: But before Arabic numerals, lots of people in Europe wrote numbers with Roman numerals. For starters, "I" means one. So this is one, two, three. The numbers around the sundial change back to Roman numerals. An image illustrates the Roman numerals for one, two, and three. MOBY: Beep. TIM: Right. "V" means five. And instead of writing four "I’s" for four, you write an "I" in front of a "V." In fact, any time a small number comes immediately before a larger number, the smaller is subtracted from the larger. That's called subtractive notation. An image illustrates Roman numerals for four and five. TIM: But whenever a smaller number comes after a large number, the numbers add up. So "VI" means six, because five plus one is six. Seven, eight, uh "X" means ten. So "IX" is nine. 11 and 12. There. An image illustrates Roman numerals for six, seven, eight, nine, ten, eleven, and twelve. There. MOBY: Beep. Moby examines the monitor on his arm. The Roman numerals indicate that the time is "IV" and "XVI." TIM: Well, the hour is "IV." That's four. And "X" plus "V" plus "I," ten plus five plus one, equals sixteen. So it's four-sixteen right now. We're going to need to figure out some bigger numbers if we're going to fix your time machine. An image illustrates Roman numerals for the time four sixteen o'clock. TIM: Hey, wait a minute. There weren't newsboys in ancient Rome. And this calendar won't even be used for hundreds of years. Well, anyway. Tim sees a young man selling newspapers. The paper is dated in Roman numerals September "VIII, CXIX." TIM: Well, September eighth is easy enough, but the year is a little trickier. I remember that "C" means one hundred. But how do you know whether the "I" is supposed to be added to the first "X" or subtracted from the second "X?" An image shows the Roman numerals "CXIX." "I" equals 1, "V" equals 5, "X" equals 10, and "C" equals 100. MOBY: Beep. TIM: Well, I seem to recall that Roman numerals are generally read left to right and from the largest to the smallest number. But before you could read the number fully, you've got to check for subtractive notation first. The Roman numerals "CXIX" are highlighted as Tim describes them. TIM: If you have any smaller number appearing to the left of a larger number, pair those two together in your mind. In this case, the "I" is smaller in value than both "X’s" but it's physically located to the left of only the second "X." So it goes with that one to make nine. Then I can add the two simplified terms to get ten plus nine. Nineteen. The Roman numerals "CXIX" are highlighted to show "IX." TIM: So this is what the year one-hundred-and-nineteen looks like. The image shows "C" plus "X" plus "IX," or one hundred plus 10 plus 9 equals one-hundred-nineteen. TIM: Hey, Moby. Remember how the new library in our town had a complicated-looking date stamped on it? An image shows a public library with the Roman numeral "MCMXCVII" inscribed on the front. TIM: The biggest numeral was "M," which means one thousand. To figure out the rest we should find any instances of smaller numbers being to the left of bigger numbers and separate those pairs. Since the first "C" is both smaller than the second "M" and the "M" to the left of it, you read it as one-thousand minus one-hundred, or nine-hundred. And since "X" is to the left of the larger "C," we subtract ten from one-hundred to get ninety. Finally, we add. The image shows "M" plus "CM" plus "XC" plus "VII," or one thousand plus nine hundred plus ninety plus seven equals nineteen-ninety-seven. MOBY: Beep. TIM: Yeah, well, you might also run across "L," which stands for fifty, and "D," or five hundred. Images show "L" equals fifty and "D" equals five hundred. TIM: Another thing to keep in mind is that you can only subtract the number when it's one power of ten less than the one you're subtracting from, so you can subtract one from ten, but not from one-hundred or a thousand. Images show that "IX" equals 9, "XCIX" equals 99, and "CMXCIX" equals 999. TIM: Oh, and you can't ever subtract more than one numeral from another. An image shows that "IV" equals 4. TIM: Uh, where'd you get him? Moby rides up to Tim on a donkey. The donkey is braying. MOBY: Beep. TIM: Jupiter did what, now? Come on, give me your arm. Moby holds out his arm. Tim keys in the Roman numerals for the year two-thousand-seven. Moby's monitor displays the numerals "MMVII." TIM: One thousand, two thousand, seven. The two teleport to Tim and Moby's front yard. The donkey is still with them. TIM: That's not coming in the house. Category:BrainPOP Transcripts Category:BrainPOP Math Transcripts